| Herniaria ciliolata | GB, VC1 West Cornwall, Lizard | James Henry Augustus Steuart | James Henry Augustus Steuart | 7/1894 | ABS |
| Gladiolus illyricus | GB, VC11 South Hampshire, New Forest | George Claridge Druce James Henry Augustus Steuart | Harold Stuart Thompson James Henry Augustus Steuart | 6/1884 2/7/1889 | BIRM |
| Gentianella anglica | GB, VC10 Isle of Wight, Bembridge | James Henry Augustus Steuart | Botanical Exchange Club of The British Isles James Henry Augustus Steuart William Hadden Beeby | 20/6/1889 to 27/6/1889 | SLBI |
| Gentianella anglica | GB, VC10 Isle of Wight, Ventnor | James Henry Augustus Steuart | Botanical Exchange Club of The British Isles James Henry Augustus Steuart William Hadden Beeby | 20/6/1889 to 27/6/1889 | SLBI |
| Gentianella anglica | GB, VC10 Isle of Wight, Ventnor | James Henry Augustus Steuart | Botanical Exchange Club of The British Isles William Hunt Painter | 20/6/1889 to 27/6/1889 | ABS |
| Gentianella anglica | GB, VC10 Isle of Wight, Ventnor | James Henry Augustus Steuart | Botanical Exchange Club of The British Isles James Henry Augustus Steuart William Hunt Painter | 20/7/1889 to 27/7/1889 | ABS |
| Gentianella anglica | GB, VC10 Isle of Wight, Ventnor and Bambridge Downs | James Henry Augustus Steuart | James Henry Augustus Steuart Botanical Exchange Club of The British Isles Augustin Ley | 20/6/1889 to 27/6/1889 | BIRM |
| Galium | GB, VC3 South Devon, Exeter | James Henry Augustus Steuart | Botanical Exchange Club of The British Isles Augustin Ley James Alfred Wheldon | 7/7/1891 | BIRM |
| Filago pyramidata | GB, VC10 Isle of Wight, Bowcombe | James Henry Augustus Steuart | Harold Stuart Thompson James Henry Augustus Steuart James Henry Augustus Steuart | 8/1888 | BIRM |
| Euphorbia cyparissias | GB, VC26 West Suffolk, Tuddenham | W J Cross | James Henry Augustus Steuart | 31/5/1893 | ABS |
| Euphorbia cyparissias | GB, VC70 Cumberland, Egremont | Joseph Adair | James Henry Augustus Steuart Joseph Adair | 5/1893 | ABS |
| Erucastrum gallicum | GB, VC29 Cambridgeshire, Newmarket Heath | J W F Cross | James Henry Augustus Steuart | 9/1890 | SLBI |
| Erica ciliaris x tetralix = E. x watsonii | GB, VC1 West Cornwall, Chacewater | James Henry Augustus Steuart | Watson Botanical Exchange Club Harold Stuart Thompson National Museum of Wales | 9/1894 | BIRM |
| Erica ciliaris x tetralix = E. x watsonii | GB, VC1 West Cornwall, Chacewater | James Henry Augustus Steuart | Watson Botanical Exchange Club National Museum of Wales | 9/1894 | SLBI |
| Echium plantagineum | GB, VC1 West Cornwall, Saint Just | James Henry Augustus Steuart | Harold Stuart Thompson James Henry Augustus Steuart | 7/1884 | BIRM |
| Coincya monensis | GB, VC29 Cambridgeshire, Newmarket Heath Cultivated | William J Cross | James Henry Augustus Steuart William Hunt Painter William J Cross | | ABS |
| Clinopodium menthifolium | GB, VC10 Isle of Wight, Apesdown | James Henry Augustus Steuart | Watson Botanical Exchange Club Harold Stuart Thompson National Museum of Wales | 9/1888 | BIRM |
| Chenopodium murale | GB, VC10 Isle of Wight, Newchurch | James Henry Augustus Steuart | James Henry Augustus Steuart | 9/1892 | SHYB |
| Chenopodium murale | GB, VC10 Isle of Wight, Newchurch | James Henry Augustus Steuart | James Henry Augustus Steuart | 9/1892 | ABS |
| Cerastium pumilum | GB, VC10 Isle of Wight, Isle of Wight | James Henry Augustus Steuart | William Robert Sherrin | 5/1889 | SLBI |
+ | Cerastium pumilum | GB, VC10 Isle of Wight, Sandown | James Henry Augustus Steuart | Charles Bailey James Alfred Wheldon | 1889 | MANCH |
| Cerastium pumilum | GB, VC10 Isle of Wight, Sandown | James Henry Augustus Steuart | Botanical Exchange Club of The British Isles James Alfred Wheldon | 1889 | BIRM |
| Cerastium pumilum | GB, VC10 Isle of Wight, Sandown | James Henry Augustus Steuart | Botanical Exchange Club of The British Isles Allan Octavian Hume Frederick Townsend James Alfred Wheldon | 1889 | SLBI |
| Centaurium erythraea | GB, VC10 Isle of Wight, Afton Down | James Henry Augustus Steuart | | 2/7/1889 | ABS |
| Centaurium erythraea var. capitatum | GB, VC10 Isle of Wight, Freshwater | James Henry Augustus Steuart | Allan Octavian Hume James Henry Augustus Steuart | 8/1890 | SLBI |
| Centaurium erythraea | GB, VC10 Isle of Wight, Freshwater | James Henry Augustus Steuart | Augustin Ley James Henry Augustus Steuart | 8/1890 | BIRM |
| Centaurium erythraea | GB, VC10 Isle of Wight, Freshwater | James Henry Augustus Steuart | James Henry Augustus Steuart William Hunt Painter | 8/1890 | ABS |
| Centaurium erythraea var. capitatum | GB, VC10 Isle of Wight, Freshwater, Afton Down | James Henry Augustus Steuart | William Hadden Beeby | 12/7/1891 | SLBI |
| Centaurium erythraea | GB, VC10 Isle of Wight, Freshwater, Afton Down | James Henry Augustus Steuart | George Goode Harold Stuart Thompson | 2/7/1890 | BIRM |
| Carex sylvatica | GB, VC10 Isle of Wight, Bembridge, Steyne Wood | James Henry Augustus Steuart | Royal Botanic Gardens, Kew James Alfred Wheldon | 2/5/1893 | E |
| Carex riparia | GB, VC10 Isle of Wight, Newport | James Henry Augustus Steuart | James Henry Augustus Steuart | 6/1889 | E |
| Carex pulla | GB, VC88 Mid Perthshire, Beinn Heasgarnich | R H McCobrum | James Henry Augustus Steuart | 19/7/1888 | ABS |
| Carex pulla | GB, VC88 Mid Perthshire, Beinn Heasgarnich | R H McCobrum | Harold Stuart Thompson James Henry Augustus Steuart | 19/7/1888 | BIRM |
| Carex paniculata x remota = C. x boenninghauseniana | | James Henry Augustus Steuart | Edward Francis Linton James Henry Augustus Steuart | 5/1893 to 6/1893 | BM |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC10 Isle of Wight, Newchurch | James Henry Augustus Steuart | Charles Bailey Frederick Thompson Mott James Henry Augustus Steuart Henry Peter Reader Thomas Thorp | 5/1893 | MANCH |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC10 Isle of Wight, Newchurch | James Henry Augustus Steuart | Arthur Bennett | 5/1893 | BM |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC10 Isle of Wight, Newchurch | James Henry Augustus Steuart | James Henry Augustus Steuart | 5/1893 6/1893 | BM |
| Carex ovalis | GB, VC37 Worcestershire, Malvern Wells | James Henry Augustus Steuart | James Henry Augustus Steuart William Charles Barton | 8/1892 | BM |
| Carex ovalis | GB, VC37 Worcestershire, Malvern Wells | James Henry Augustus Steuart | Albert Bruce Jackson James Henry Augustus Steuart | 8/1892 | BM |
| Carex ovalis | GB, VC37 Worcestershire, Malvern Wells | James Henry Augustus Steuart | James Henry Augustus Steuart | 7/1892 | BM |